1. Economically Optimal Rate for Nutrient Application to Maize in the Semi-deciduous Forest Zone of Ghana
- Author
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Benedicta Essel, Andrews Opoku, Robert C. Abaidoo, and Nana Ewusi-Mensah
- Subjects
Optimization ,0106 biological sciences ,Potassium ,Net return to fertilizer ,Soil Science ,chemistry.chemical_element ,Plant Science ,engineering.material ,01 natural sciences ,Nutrient ,Nutrient use efficiency ,Mathematics ,Original Paper ,Acrisol ,Phosphorus ,Semi-deciduous ,Asymptotic function ,04 agricultural and veterinary sciences ,Factorial experiment ,Nitrogen ,Cost to grain price ratio ,Agronomy ,chemistry ,040103 agronomy & agriculture ,engineering ,0401 agriculture, forestry, and fisheries ,Fertilizer response ,Fertilizer ,Agronomy and Crop Science ,010606 plant biology & botany - Abstract
Low inherent nitrogen (N), phosphorus (P), and potassium (K) contents of smallholder farms limit maize grain yield. Maize grain yield response to N, P, and K mineral fertilizer application and economically optimal rates for nitrogen (EORN), phosphorus (EORP), and potassium (EORK) were evaluated on a Ferric Acrisol within the semi-deciduous forest zone of Ghana. The nutrient rates evaluated were N (0, 30, 60, 90, and 120 kg N ha−1), P (0, 30, 60, and 90 kg ha−1 P2O5), and K (0, 30, 60 and 90 kg ha−1 K2O). The treatments were arranged in a randomized complete block with three replications using an incomplete factorial design. Nutrient responses were determined using asymptotic quadratic-plus plateau functions. The best nitrogen rate for all P and K levels was 60 kg ha−1, which gave grain yield of 5 t ha−1. Nitrogen uptake, N agronomic and N recovery efficiencies peaked at 60 kg N ha−1 while N partial factor productivity declined with increasing N application rate. Cost to grain price ratios (CP) were 1.29, 1.65, and 1.65 for N, P, and K, respectively. The EORN was 61 kg ha−1, 32% less than the recommended 90 kg N ha−1 for maize production in the semi-deciduous forest zone of Ghana. Nitrogen application had the lowest CP ratio, making its application economically profitable than P and K. The findings suggest that the application of N at 61 kg N ha−1 to maize is economically profitable than at higher application rates. However, further studies should be conducted on farmers’ fields to validate the results obtained.
- Published
- 2020